Why does mercury end up in tuna?

The oceans contain traces of mercury that accumulate in the tissues of large fish. The larger and longer-lived the species, the higher its concentration. That’s why some varieties of tuna can contain much higher levels than others.

Among the effects that are being sought to be avoided are:

• Long-term neurological problems
• Risks in pregnant women and children
• Toxic accumulation in essential organs

The differences between types of tuna that almost no one checks

A crucial detail revealed by experts is that there are three main types of tuna, and not all of them have the same level of mercury.

1. Skipjack tuna

It is the smallest and contains the least mercury. It usually appears on labels as:

• “Light” tuna
• Light tuna
• Skipjack tuna

2. Yellowfin tuna

It’s larger than the listed size. It has moderate levels of mercury. In many commercial brands, it appears as “light tuna” without further specification.

3. Albacore tuna

It has the highest mercury content. It is usually listed as:

• “Albacore tuna”
• “Albacore”
• “Albacore”

This is the type that is recommended to limit as much as possible, especially in pregnant women, children, or people who consume tuna several times a week.

How to choose a truly safe can of tuna

To avoid risks and consume a better quality product, experts recommend reviewing these points:

✔️ Check the species type on the label

If it’s not specified, it’s best to avoid that can. Brands with transparent labeling tend to operate with higher standards.

✔️ Prefer skipjack tuna

It usually has a better nutritional profile and minimal mercury levels.

✔️ Avoid cans with vague terms

Expressions like “tuna mix” or “generic tuna” should raise suspicions.

✔️ Check the type of oil or water

The calorie content changes significantly:

• In water: lighter
• In oil: denser and with more fat

How much tuna is recommended to consume per week?

Nutritional guidelines published by specialists recommend:

• Adults: 2 to 3 servings of skipjack tuna per week
• Children and pregnant women: maximum 1 or 2 portions, always of skipjack tuna

Albacore tuna should be limited to an occasional portion due to its higher mercury levels.

Healthy alternatives to reduce the risk

If you want to continue eating fish without worrying about mercury exposure, experts suggest including these foods:

• Sardines
• Small mackerel
• Wild salmon
• Rainbow trout

All are economical options, with high omega-3 content and low levels of heavy metals.

Conclusion

Tuna remains an excellent food, but not all varieties are created equal. Understanding which species you’re buying, how to read the label, and what the scientific community recommends can make a huge difference to your long-term health.

Thanks to analysis by the Hiper Hábitos channel, thousands of people are learning to choose better and avoid the most common mistake: buying any can without checking the type of tuna it contains.

If this topic surprised you, check your cans at home… you might discover something you’ve never noticed before.